/* Copyright (c) 2020 XEPIC Corporation Limited */
/*
 * Copyright (c) 2002-2018 Stephen Williams (steve@icarus.com)
 *
 *    This source code is free software; you can redistribute it
 *    and/or modify it in source code form under the terms of the GNU
 *    General Public License as published by the Free Software
 *    Foundation; either version 2 of the License, or (at your option)
 *    any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
 * USA.
 */

/* The sys_priv.h include must be before the lxt_write.h include! */
#include "lxt_write.h"
#include "sys_priv.h"
#include "vcd_priv.h"

/*
 * This file contains the implementations of the LXT related functions.
 */

#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

#include "ivl_alloc.h"
#include "stringheap.h"

static char *dump_path = NULL;
static struct lt_trace *dump_file = NULL;

static struct t_vpi_time zero_delay = {vpiSimTime, 0, 0, 0.0};

struct vcd_info {
  vpiHandle item;
  vpiHandle cb;
  struct t_vpi_time time;
  struct lt_symbol *sym;
  struct vcd_info *next;
  struct vcd_info *dmp_next;
  int scheduled;
};

static struct vcd_info *vcd_list = NULL;
static struct vcd_info *vcd_dmp_list = NULL;
static PLI_UINT64 vcd_cur_time = 0;
static int dump_is_off = 0;
static long dump_limit = 0;
static int dump_is_full = 0;
static int finish_status = 0;

static enum lxm_optimum_mode_e {
  LXM_NONE = 0,
  LXM_SPACE = 1,
  LXM_SPEED = 2
} lxm_optimum_mode = LXM_SPEED;

/*
 * The lxt_scope head and current pointers are used to keep a scope
 * stack that can be accessed from the bottom. The lxt_scope_head
 * points to the first (bottom) item in the stack and
 * lxt_scope_current points to the last (top) item in the stack. The
 * push_scope and pop_scope methods manipulate the stack.
 */
struct lxt_scope {
  struct lxt_scope *next, *prev;
  char *name;
  int len;
};

static struct lxt_scope *lxt_scope_head = NULL, *lxt_scope_current = NULL;

static void push_scope(const char *name) {
  struct lxt_scope *t = (struct lxt_scope *)calloc(1, sizeof(struct lxt_scope));

  t->name = strdup(name);
  t->len = strlen(name);

  if (!lxt_scope_head) {
    lxt_scope_head = lxt_scope_current = t;
  } else {
    lxt_scope_current->next = t;
    t->prev = lxt_scope_current;
    lxt_scope_current = t;
  }
}

static void pop_scope(void) {
  struct lxt_scope *t;

  assert(lxt_scope_current);

  t = lxt_scope_current->prev;
  free(lxt_scope_current->name);
  free(lxt_scope_current);
  lxt_scope_current = t;
  if (lxt_scope_current) {
    lxt_scope_current->next = 0;
  } else {
    lxt_scope_head = 0;
  }
}

/*
 * This function uses the scope stack to generate a hierarchical
 * name. Scan the scope stack from the bottom up to construct the
 * name.
 */
static char *create_full_name(const char *name) {
  char *n, *n2;
  int len = 0;
  int is_esc_id = is_escaped_id(name);
  struct lxt_scope *t = lxt_scope_head;

  /* Figure out how long the combined string will be. */
  while (t) {
    len += t->len + 1;
    t = t->next;
  }

  len += strlen(name) + 1;
  if (is_esc_id) len += 1;

  /* Allocate a string buffer. */
  n = n2 = malloc(len);

  t = lxt_scope_head;
  while (t) {
    strcpy(n2, t->name);
    n2 += t->len;
    *n2 = '.';
    n2++;
    t = t->next;
  }

  if (is_esc_id) {
    *n2 = '\\';
    n2++;
  }
  strcpy(n2, name);
  n2 += strlen(n2);
  assert((n2 - n + 1) == len);

  return n;
}

static void show_this_item(struct vcd_info *info) {
  s_vpi_value value;

  if (vpi_get(vpiType, info->item) == vpiRealVar) {
    value.format = vpiRealVal;
    vpi_get_value(info->item, &value);
    lt_emit_value_double(dump_file, info->sym, 0, value.value.real);

  } else {
    value.format = vpiBinStrVal;
    vpi_get_value(info->item, &value);
    lt_emit_value_bit_string(dump_file, info->sym, 0 /* array row */,
                             value.value.str);
  }
}

static void show_this_item_x(struct vcd_info *info) {
  if (vpi_get(vpiType, info->item) == vpiRealVar) {
    /* Should write a NaN here? */
  } else {
    lt_emit_value_bit_string(dump_file, info->sym, 0, "x");
  }
}

/*
 * managed qsorted list of scope names for duplicates bsearching
 */

struct vcd_names_list_s lxt_tab;

static int dumpvars_status = 0; /* 0:fresh 1:cb installed, 2:callback done */
static PLI_UINT64 dumpvars_time;
__inline__ static int dump_header_pending(void) { return dumpvars_status != 2; }

/*
 * This function writes out all the traced variables, whether they
 * changed or not.
 */
static void vcd_checkpoint(void) {
  struct vcd_info *cur;

  for (cur = vcd_list; cur; cur = cur->next) show_this_item(cur);
}

static void vcd_checkpoint_x(void) {
  struct vcd_info *cur;

  for (cur = vcd_list; cur; cur = cur->next) show_this_item_x(cur);
}

static PLI_INT32 variable_cb_2(p_cb_data cause) {
  struct vcd_info *info = vcd_dmp_list;
  PLI_UINT64 now = timerec_to_time64(cause->time);

  if (now != vcd_cur_time) {
    lt_set_time64(dump_file, now);
    vcd_cur_time = now;
  }

  do {
    show_this_item(info);
    info->scheduled = 0;
  } while ((info = info->dmp_next) != 0);

  vcd_dmp_list = 0;

  return 0;
}

static PLI_INT32 variable_cb_1(p_cb_data cause) {
  struct t_cb_data cb;
  struct vcd_info *info = (struct vcd_info *)cause->user_data;

  if (dump_is_full) return 0;
  if (dump_is_off) return 0;
  if (dump_header_pending()) return 0;
  if (info->scheduled) return 0;

  if ((dump_limit > 0) && (ftell(dump_file->handle) > dump_limit)) {
    dump_is_full = 1;
    vpi_printf(
        "WARNING: Dump file limit (%ld bytes) "
        "exceeded.\n",
        dump_limit);
    return 0;
  }

  if (!vcd_dmp_list) {
    cb = *cause;
    cb.time = &zero_delay;
    cb.reason = cbReadOnlySynch;
    cb.cb_rtn = variable_cb_2;
    vpi_register_cb(&cb);
  }

  info->scheduled = 1;
  info->dmp_next = vcd_dmp_list;
  vcd_dmp_list = info;

  return 0;
}

static PLI_INT32 dumpvars_cb(p_cb_data cause) {
  if (dumpvars_status != 1) return 0;

  dumpvars_status = 2;

  dumpvars_time = timerec_to_time64(cause->time);
  vcd_cur_time = dumpvars_time;

  if (!dump_is_off) {
    lt_set_time64(dump_file, dumpvars_time);
    vcd_checkpoint();
  }

  return 0;
}

static PLI_INT32 finish_cb(p_cb_data cause) {
  struct vcd_info *cur, *next;

  if (finish_status != 0) return 0;

  finish_status = 1;

  dumpvars_time = timerec_to_time64(cause->time);
  if (!dump_is_off && !dump_is_full && dumpvars_time != vcd_cur_time) {
    lt_set_time64(dump_file, dumpvars_time);
  }

  for (cur = vcd_list; cur; cur = next) {
    next = cur->next;
    free(cur);
  }
  vcd_list = 0;

  vcd_names_delete(&lxt_tab);
  nexus_ident_delete();
  free(dump_path);
  dump_path = 0;

  return 0;
}

__inline__ static int install_dumpvars_callback(void) {
  struct t_cb_data cb;

  if (dumpvars_status == 1) return 0;

  if (dumpvars_status == 2) {
    vpi_printf(
        "LXT warning: $dumpvars ignored, previously"
        " called at simtime %" PLI_UINT64_FMT "\n",
        dumpvars_time);
    return 1;
  }

  cb.time = &zero_delay;
  cb.reason = cbReadOnlySynch;
  cb.cb_rtn = dumpvars_cb;
  cb.user_data = 0x0;
  cb.obj = 0x0;

  vpi_register_cb(&cb);

  cb.reason = cbEndOfSimulation;
  cb.cb_rtn = finish_cb;

  vpi_register_cb(&cb);

  dumpvars_status = 1;
  return 0;
}

static PLI_INT32 sys_dumpoff_calltf(ICARUS_VPI_CONST PLI_BYTE8 *name) {
  s_vpi_time now;
  PLI_UINT64 now64;

  (void)name; /* Parameter is not used. */

  if (dump_is_off) return 0;

  dump_is_off = 1;

  if (dump_file == 0) return 0;
  if (dump_header_pending()) return 0;

  now.type = vpiSimTime;
  vpi_get_time(0, &now);
  now64 = timerec_to_time64(&now);

  if (now64 > vcd_cur_time) {
    lt_set_time64(dump_file, now64);
    vcd_cur_time = now64;
  }

  lt_set_dumpoff(dump_file);
  vcd_checkpoint_x();

  return 0;
}

static PLI_INT32 sys_dumpon_calltf(ICARUS_VPI_CONST PLI_BYTE8 *name) {
  s_vpi_time now;
  PLI_UINT64 now64;

  (void)name; /* Parameter is not used. */

  if (!dump_is_off) return 0;

  dump_is_off = 0;

  if (dump_file == 0) return 0;
  if (dump_header_pending()) return 0;

  now.type = vpiSimTime;
  vpi_get_time(0, &now);
  now64 = timerec_to_time64(&now);

  if (now64 > vcd_cur_time) {
    lt_set_time64(dump_file, now64);
    vcd_cur_time = now64;
  }

  lt_set_dumpon(dump_file);
  vcd_checkpoint();

  return 0;
}

static PLI_INT32 sys_dumpall_calltf(ICARUS_VPI_CONST PLI_BYTE8 *name) {
  s_vpi_time now;
  PLI_UINT64 now64;

  (void)name; /* Parameter is not used. */

  if (dump_is_off) return 0;
  if (dump_file == 0) return 0;
  if (dump_header_pending()) return 0;

  now.type = vpiSimTime;
  vpi_get_time(0, &now);
  now64 = timerec_to_time64(&now);

  if (now64 > vcd_cur_time) {
    lt_set_time64(dump_file, now64);
    vcd_cur_time = now64;
  }

  vcd_checkpoint();

  return 0;
}

static void *close_dumpfile(void) {
  lt_close(dump_file);
  dump_file = NULL;
  return NULL;
}

static void open_dumpfile(vpiHandle callh) {
  if (dump_path == 0) dump_path = strdup("dump.lxt");

  dump_file = lt_init(dump_path);

  if (dump_file == 0) {
    vpi_printf("LXT Error: %s:%d: ", vpi_get_str(vpiFile, callh),
               (int)vpi_get(vpiLineNo, callh));
    vpi_printf("Unable to open %s for output.\n", dump_path);
    vpi_control(vpiFinish, 1);
    free(dump_path);
    dump_path = 0;
    return;
  } else {
    int prec = vpi_get(vpiTimePrecision, 0);

    vpi_printf("LXT info: dumpfile %s opened for output.\n", dump_path);

    assert(prec >= -15);
    lt_set_timescale(dump_file, prec);

    lt_set_initial_value(dump_file, 'x');
    lt_set_clock_compress(dump_file);

    atexit((void (*)(void))close_dumpfile);
  }
}

static PLI_INT32 sys_dumpfile_calltf(ICARUS_VPI_CONST PLI_BYTE8 *name) {
  vpiHandle callh = vpi_handle(vpiSysTfCall, 0);
  vpiHandle argv = vpi_iterate(vpiArgument, callh);
  char *path;

  /* $dumpfile must be called before $dumpvars starts! */
  if (dumpvars_status != 0) {
    char msg[64];
    snprintf(msg, sizeof(msg),
             "LXT warning: %s:%d:", vpi_get_str(vpiFile, callh),
             (int)vpi_get(vpiLineNo, callh));
    msg[sizeof(msg) - 1] = 0;
    vpi_printf("%s %s called after $dumpvars started,\n", msg, name);
    vpi_printf("%*s using existing file (%s).\n", (int)strlen(msg), " ",
               dump_path);
    vpi_free_object(argv);
    return 0;
  }

  path = get_filename_with_suffix(callh, name, vpi_scan(argv), "lxt");
  vpi_free_object(argv);
  if (!path) return 0;

  if (dump_path) {
    vpi_printf("LXT warning: %s:%d: ", vpi_get_str(vpiFile, callh),
               (int)vpi_get(vpiLineNo, callh));
    vpi_printf("Overriding dump file %s with %s.\n", dump_path, path);
    free(dump_path);
  }
  dump_path = path;

  return 0;
}

/*
 * The LXT1 format has no concept of file flushing.
 */
static PLI_INT32 sys_dumpflush_calltf(ICARUS_VPI_CONST PLI_BYTE8 *name) {
  (void)name; /* Parameter is not used. */
  return 0;
}

static PLI_INT32 sys_dumplimit_calltf(ICARUS_VPI_CONST PLI_BYTE8 *name) {
  vpiHandle callh = vpi_handle(vpiSysTfCall, 0);
  vpiHandle argv = vpi_iterate(vpiArgument, callh);
  s_vpi_value val;

  (void)name; /* Parameter is not used. */

  /* Get the value and set the dump limit. */
  val.format = vpiIntVal;
  vpi_get_value(vpi_scan(argv), &val);
  dump_limit = val.value.integer;

  vpi_free_object(argv);
  return 0;
}

static void scan_item(unsigned depth, vpiHandle item, int skip) {
  struct t_cb_data cb;
  struct vcd_info *info;

  const char *name;
  const char *ident;
  int nexus_id;

  switch (vpi_get(vpiType, item)) {
    case vpiMemoryWord:
      if (vpi_get(vpiConstantSelect, item) == 0) {
        /* Turn a non-constant array word select into a
         * constant word select. */
        vpiHandle array = vpi_handle(vpiParent, item);
        PLI_INT32 idx = vpi_get(vpiIndex, item);
        item = vpi_handle_by_index(array, idx);
      }
      // fallthrough
    case vpiIntegerVar:
    case vpiBitVar:
    case vpiByteVar:
    case vpiShortIntVar:
    case vpiIntVar:
    case vpiLongIntVar:
    case vpiTimeVar:
    case vpiReg:
    case vpiNet:

      /* An array word is implicitly escaped so look for an
       * escaped identifier that this could conflict with. */
      if (vpi_get(vpiType, item) == vpiMemoryWord &&
          vpi_handle_by_name(vpi_get_str(vpiFullName, item), 0)) {
        vpi_printf(
            "LXT warning: dumping array word %s will "
            "conflict with an escaped identifier.\n",
            vpi_get_str(vpiFullName, item));
      }

      if (skip || vpi_get(vpiAutomatic, item)) break;

      name = vpi_get_str(vpiName, item);
      nexus_id = vpi_get(_vpiNexusId, item);
      if (nexus_id) {
        ident = find_nexus_ident(nexus_id);
      } else {
        ident = 0;
      }

      if (!ident) {
        char *tmp = create_full_name(name);
        ident = strdup_sh(&name_heap, tmp);
        free(tmp);

        if (nexus_id) set_nexus_ident(nexus_id, ident);

        info = malloc(sizeof(*info));

        info->time.type = vpiSimTime;
        info->item = item;
        info->sym = lt_symbol_add(dump_file, ident, 0 /* array rows */,
                                  vpi_get(vpiLeftRange, item),
                                  vpi_get(vpiRightRange, item), LT_SYM_F_BITS);
        info->scheduled = 0;

        cb.time = &info->time;
        cb.user_data = (char *)info;
        cb.value = NULL;
        cb.obj = item;
        cb.reason = cbValueChange;
        cb.cb_rtn = variable_cb_1;

        info->next = vcd_list;
        vcd_list = info;

        info->cb = vpi_register_cb(&cb);

      } else {
        char *n = create_full_name(name);
        lt_symbol_alias(dump_file, ident, n, vpi_get(vpiSize, item) - 1, 0);
        free(n);
      }

      break;

    case vpiRealVar:

      if (skip || vpi_get(vpiAutomatic, item)) break;

      name = vpi_get_str(vpiName, item);
      {
        char *tmp = create_full_name(name);
        ident = strdup_sh(&name_heap, tmp);
        free(tmp);
      }
      info = malloc(sizeof(*info));

      info->time.type = vpiSimTime;
      info->item = item;
      info->sym = lt_symbol_add(dump_file, ident, 0 /* array rows */,
                                vpi_get(vpiSize, item) - 1, 0, LT_SYM_F_DOUBLE);
      info->scheduled = 0;

      cb.time = &info->time;
      cb.user_data = (char *)info;
      cb.value = NULL;
      cb.obj = item;
      cb.reason = cbValueChange;
      cb.cb_rtn = variable_cb_1;

      info->next = vcd_list;
      vcd_list = info;

      info->cb = vpi_register_cb(&cb);

      break;

    case vpiModule:
    case vpiGenScope:
    case vpiFunction:
    case vpiTask:
    case vpiNamedBegin:
    case vpiNamedFork:

      if (depth > 0) {
        const char *fullname = vpi_get_str(vpiFullName, item);
        /* list of types to iterate upon */
        static int types[] = {/* Value */
                              /* vpiNamedEvent, */
                              vpiNet,
                              /* vpiParameter, */
                              vpiReg, vpiVariables,
                              /* Scope */
                              vpiFunction, vpiGenScope, vpiModule,
                              vpiNamedBegin, vpiNamedFork, vpiTask, -1};
        int i;
        int nskip = (vcd_names_search(&lxt_tab, fullname) != 0);

#if 0
		  vpi_printf("LXT info: scanning scope %s, %u levels\n",
		             fullname, depth);
#endif

        if (nskip) {
          vpi_printf(
              "LXT warning: ignoring signals in "
              "previously scanned scope %s\n",
              fullname);
        } else {
          vcd_names_add(&lxt_tab, fullname);
        }

        name = vpi_get_str(vpiName, item);

        push_scope(name);

        for (i = 0; types[i] > 0; i++) {
          vpiHandle hand;
          vpiHandle argv = vpi_iterate(types[i], item);
          while (argv && (hand = vpi_scan(argv))) {
            scan_item(depth - 1, hand, nskip);
          }
        }

        pop_scope();
      }
      break;

    default:
      vpi_printf(
          "LXT warning: $dumpvars: Unsupported parameter "
          "type (%s)\n",
          vpi_get_str(vpiType, item));
  }
}

static int draw_scope(vpiHandle item) {
  int depth;
  const char *name;

  vpiHandle scope = vpi_handle(vpiScope, item);
  if (!scope) return 0;

  depth = 1 + draw_scope(scope);
  name = vpi_get_str(vpiName, scope);

  push_scope(name);

  return depth;
}

static PLI_INT32 sys_dumpvars_calltf(ICARUS_VPI_CONST PLI_BYTE8 *name) {
  vpiHandle callh = vpi_handle(vpiSysTfCall, 0);
  vpiHandle argv = vpi_iterate(vpiArgument, callh);
  vpiHandle item;
  s_vpi_value value;
  unsigned depth = 0;

  (void)name; /* Parameter is not used. */

  if (dump_file == 0) {
    open_dumpfile(callh);
    if (dump_file == 0) {
      if (argv) vpi_free_object(argv);
      return 0;
    }
  }

  if (install_dumpvars_callback()) {
    if (argv) vpi_free_object(argv);
    return 0;
  }

  /* Get the depth if it exists. */
  if (argv) {
    value.format = vpiIntVal;
    vpi_get_value(vpi_scan(argv), &value);
    depth = value.value.integer;
  }
  if (!depth) depth = 10000;

  /* This dumps all the modules in the design if none are given. */
  if (!argv || !(item = vpi_scan(argv))) {
    argv = vpi_iterate(vpiModule, 0x0);
    assert(argv); /* There must be at least one top level module. */
    item = vpi_scan(argv);
  }

  for (; item; item = vpi_scan(argv)) {
    int dep = draw_scope(item);

    scan_item(depth, item, 0);
    /* The scope list must be sorted after we scan an item.  */
    vcd_names_sort(&lxt_tab);

    while (dep--) pop_scope();
  }

  /* Most effective compression. */
  if (lxm_optimum_mode == LXM_SPACE) {
    lt_set_no_interlace(dump_file);
  }

  return 0;
}

void sys_lxt_register(void) {
  int idx;
  struct t_vpi_vlog_info vlog_info;
  s_vpi_systf_data tf_data;
  vpiHandle res;

  /* Scan the extended arguments, looking for lxt optimization flags. */
  vpi_get_vlog_info(&vlog_info);

  /* The "speed" option is not used in this dumper. */
  for (idx = 0; idx < vlog_info.argc; idx += 1) {
    if (strcmp(vlog_info.argv[idx], "-lxt-space") == 0) {
      lxm_optimum_mode = LXM_SPACE;

    } else if (strcmp(vlog_info.argv[idx], "-lxt-speed") == 0) {
      lxm_optimum_mode = LXM_SPEED;
    }
  }

  /* All the compiletf routines are located in vcd_priv.c. */

  tf_data.type = vpiSysTask;
  tf_data.tfname = "$dumpall";
  tf_data.calltf = sys_dumpall_calltf;
  tf_data.compiletf = sys_no_arg_compiletf;
  tf_data.sizetf = 0;
  tf_data.user_data = "$dumpall";
  res = vpi_register_systf(&tf_data);
  vpip_make_systf_system_defined(res);

  tf_data.type = vpiSysTask;
  tf_data.tfname = "$dumpfile";
  tf_data.calltf = sys_dumpfile_calltf;
  tf_data.compiletf = sys_one_string_arg_compiletf;
  tf_data.sizetf = 0;
  tf_data.user_data = "$dumpfile";
  res = vpi_register_systf(&tf_data);
  vpip_make_systf_system_defined(res);

  tf_data.type = vpiSysTask;
  tf_data.tfname = "$dumpflush";
  tf_data.calltf = sys_dumpflush_calltf;
  tf_data.compiletf = sys_no_arg_compiletf;
  tf_data.sizetf = 0;
  tf_data.user_data = "$dumpflush";
  res = vpi_register_systf(&tf_data);
  vpip_make_systf_system_defined(res);

  tf_data.type = vpiSysTask;
  tf_data.tfname = "$dumplimit";
  tf_data.calltf = sys_dumplimit_calltf;
  tf_data.compiletf = sys_one_numeric_arg_compiletf;
  tf_data.sizetf = 0;
  tf_data.user_data = "$dumplimit";
  res = vpi_register_systf(&tf_data);
  vpip_make_systf_system_defined(res);

  tf_data.type = vpiSysTask;
  tf_data.tfname = "$dumpoff";
  tf_data.calltf = sys_dumpoff_calltf;
  tf_data.compiletf = sys_no_arg_compiletf;
  tf_data.sizetf = 0;
  tf_data.user_data = "$dumpoff";
  res = vpi_register_systf(&tf_data);
  vpip_make_systf_system_defined(res);

  tf_data.type = vpiSysTask;
  tf_data.tfname = "$dumpon";
  tf_data.calltf = sys_dumpon_calltf;
  tf_data.compiletf = sys_no_arg_compiletf;
  tf_data.sizetf = 0;
  tf_data.user_data = "$dumpon";
  res = vpi_register_systf(&tf_data);
  vpip_make_systf_system_defined(res);

  tf_data.type = vpiSysTask;
  tf_data.tfname = "$dumpvars";
  tf_data.calltf = sys_dumpvars_calltf;
  tf_data.compiletf = sys_dumpvars_compiletf;
  tf_data.sizetf = 0;
  tf_data.user_data = "$dumpvars";
  res = vpi_register_systf(&tf_data);
  vpip_make_systf_system_defined(res);
}
